Bought mine in early September and welded into my 1989 F250 with a 302. It took about 200 miles for things to settle down and the sound to get better. Since the double cats are essentially silencers, the Flowmaster is imperceptible when idling. In the dig, however, it really comes alive with the classic 302 growl. I immediately noticed a smoother exhaust that gave me more power. I think the 29-year-old original was a little beat up. Since I was going center-in/center-out rather thanβ¦